Blood Tests

Your healthcare provider may also measure a substance called Brain-natriuretic peptide (BNP). This is a naturally occurring hormone in your body that is elevated when the pressures in the heart are elevated because of heart failure. The BNP levels may vary over time depending on the severity of the heart failure.

Certain medications used to treat heart failure can affect the electrolytes in your body (like potassium) and may also affect your renal function. For this reason, you health care provider may need to repeat blood tests regularly, especially after adjusting medication doses.

Electrocardiogram (ECG)

An electrocardiogram of “ECG” or “EKG” is a tracing of the electrical activity of the heart. It is a non-invasive test, and involves the application of 10 stickers to your chest, arms and legs.

From the ECG the “rhythm” of the heart can be determined. Normal rhythm is called “sinus” (originating from the sinus node). Other abnormal rhythms that can be identified by the ECG include atrial fibrillation and forms of heart block.

An ECG may also provide clues that a chamber in the heart is enlarged and can sometimes show evidence of a previous heart attack.

It is normal for you to have an ECG every time you see a cardiologist.

Chest X-Ray

A Chest X-ray can give information about the size of the heart. It also looks at the lungs, and can show if there is extra fluid built up in the lungs, which may cause shortness of breath.

Echocardiogram

An echocardiogram or “ECHO” is an ultrasound of the heart (similar to other medical ultrasounds, like ultrasounds for the liver or an ultrasound of an unborn baby). It provides detailed information about the heart’s structure and function – including the pumping function of the heart as well as the function of the valves in the heart. The technology makes use of sound waves to create images and therefore does not involve any radiation exposure.

The squeezing function of the left ventricle (the main pumping chamber of the heart) can be estimated by something called the “left ventricular ejection fraction” or LVEF, which estimates the percentage of blood ejected from the left ventricle with every heartbeat. A normal LVEF is not 100% (ie. the left ventricle does not pump all of the blood with each beat), rather a normal LVEF is anything over 55%.

The 4 valves in the heart are also looked at in close detail to ensure that they open and close normally. A narrowed or tight valve is called “stenotic”, while a leaky valve is called “regurgitant”.

Normally the echocardiogram is performed through the chest wall – this is called a transthoracic ECHO. Occasionally when additional, more detailed information is required, the ECHO probe may be passed down the esophagus (the swallowing tube, which sits just behind the heart) – this is called a transesophageal ECHO.

Sometimes contrast is required to better visualize the heart. This involves inserting an intravenous and injecting a small amount of a contrast liquid.

RNA (MUGA) Radionuclide Angiogram

A RNA scan is a non-invasive test. It is a nuclear medicine test, so it involves the injection of a small amount of a radioactive tracer. After the radioactive tracer is injected, several pictures of your heart will be taken using a special camera.

The purpose of a RNA scan is to get a very accurate assessment of the left ventricular ejection fraction.

Exercise Stress Test

An exercise stress test may be performed for a number of reasons, but it is usually requested to determine a person’s risk of having coronary artery disease.

The test involves placing the usual stickers on the chest and limbs to allow for continuous monitoring of the electrical activity of the heart. Blood pressure is also checked every few minutes.

The subject then exercises, usually on a treadmill. The treadmill increases in speed and incline every few minutes. There is no set length for the stress test. The subject simply goes for as long as he or she can.

In order to obtain the most information from the stress test, there is usually a “target heart rate” set, which is based on the subject’s age.

Nuclear Stress Test

A nuclear perfusion scan is a special type of stress test that uses a small dose of an intravenous radioactive material to look at the blood flow to the heart. Pictures of the heart are taken at rest and then after stress. If there is reduced uptake of the radioactive tracer in a certain part of the heart, this may suggest that there is a narrowed or blocked artery supplying that territory of heart muscle.

Two forms are stress are possible. If possible, it is preferable to use exercise (similar to a treadmill stress test). If patients are not able to exercise, then a drug can be used to stress the heart (pharmacologic stress).

A nuclear perfusion scan is more sensitive than a plain exercise stress test at detecting coronary artery disease and determining the extent of disease.

Coronary Angiogram

A coronary angiogram is the best test to diagnose coronary artery disease. It is an invasive test that involves placing a tube (called a catheter) either in the wrist or the groin, and passing it up to the heart. Contrast dye is then injected into the arteries around the heart, and X-Ray pictures are taken.

This test allows a very detailed look at the arteries around the heart, and narrowings or blockages can be well characterized.

In general, an angiogram is a very safe test. As it is an invasive test, there are, however, some risks associated with it. Risks include bleeding or bruising, an allergic reaction to the contrast dye, or damage to the kidneys from the dye. Serious complications like a stroke, heart attack or death are extremely uncommon (less than 0.1%).

It is a day procedure. You will be awake during the test, and will be given a medication to help you relax.

Cardiopulmonary Test (CPT)

A CPT is a special type of exercise stress test. It involves exercising on a treadmill or bike. You will wear a special mask that allows for the measurement of the amount of oxygen you are consuming and the amount of carbon dioxide you are producing. This gives your doctors and nurses an idea of how well your heart is functioning.

A CPT may be repeated over time to assess the progression of heart failure

Cardiac MRI

A cardiac MRI may be used to look at the heart structure, and to look for inflammation or scar within the heart.

An MRI is a big magnet, so if cannot be performed if you have metal in your body (like a pacemaker, or metal from previous surgeries)

Because an MRI is a magnet, it does not involve any exposure to radiation

Cardiac PET Scan

A Cardiac PET scan is a specialized nuclear test that is used to take pictures of the heart. PET stands for Positron Emission Tomography.

In persons with heart disease it may be ordered to find out if the tissue of the heart is still living (or viable) and if coronary artery bypass surgery or coronary angioplasty would be beneficial.

It is also used in certain heart conditions to look for inflammation of the heart tissue.

In This Section:

About Ted Rogers Centre for Heart Research

Through an integrated program of outstanding research, world-class education, and exceptional clinical care, the Ted Rogers Centre for Heart Research will provide the world with new diagnoses, treatments and tools to help people prevent, manage and survive the devastating consequences of heart failure.